Many states are predicted to experience severe drought in the coming decades. A quantitative understanding of where our water goes will help you figure out where your conservation efforts are best spent.
California Water Management
Bay Delta Conservation Plan
This looks like a good place to start: http://waterfootprint.org/
The have a product gallery that features some of the following:
Virtually all of US almonds are grown in one of the driest regions of California.
"In one particular corner of the Central Valley, called the Westlands, irrigation has transformed desert into bountiful farmland. One idea is to stop irrigating the land and retire the Westlands from agriculture."
"California now produces close to 80 percent of the world's almonds, around 70 percent of which it exports. It's the state's largest food-crop export by a wide margin, surpassing not only other tree nuts like walnuts and pistachios, but also heavy hitters like dairy products and wine. In the last decade alone, crop yields in California have more than doubled, going from 700 million pounds in 2000 to 1.7 billion pounds last year. Blue Diamond Growers is far and away the largest player in this market. The privately held cooperative won't disclose the size of its footprint, only revealing that it's six times as large as the next-biggest of the 110 almond handlers in the state."
"Yet Westlands is almost all farmland, thanks to water from Northern California and the Sierra Nevada that the federal government pumps out of the Sacramento-San Joaquin River Delta and ships south through a series of canals and aqueducts. Throughout the 20th century, this massive transfer of water turned a large section of California desert into a bountiful — and profitable — farming region.
But ever since freshwater began flowing to the dusty west side of the valley, the landscape has been in constant flux. A decade ago, Westlands' major crop was cotton. But today, almonds are on their way to becoming king. Since 2000, the amount of land dedicated to growing almonds has more than doubled in the district, bringing the total to 75,000 acres. And now about one out of every ten almonds sold in the world comes from Westlands. The only crop more common in the district is tomatoes, which cover 80,000 acres.
Westlands farmers like Errotabere have shifted to growing almonds, and to a lesser extent, pistachios, because of the exploding international demand for them. California produces 80 percent of the almonds sold worldwide, with gross revenues of more than $6.2 billion in 2013 — nearly double what they were in 2009. Last year, almonds were California's most lucrative agricultural export by far. "We have good markets, and we're a global product that's extremely desired," said Richard Waycott, CEO of the California Almond Board.
But growing almonds in an arid climate requires lots of water. In fact, Westlands' almond orchards suck up nearly 100 billion gallons of water a year. Cotton, by contrast, needs 40 percent less water per acre, and tomatoes require about half as much water as almonds.
Also, unlike cotton and tomatoes, almonds are a "permanent" crop, meaning the land they're grown on can't lie fallow when water is scarce. "It means farmers really do need to get a hold of water in dry years in order to keep the trees alive," explained Ellen Hanak, a senior fellow at the Public Policy Institute of California and an expert on water.
But many environmentalists have little sympathy for the Westlands almond growers. They note that if farmers hadn't zealously planted water-intensive crops in the desert, they wouldn't be in such a tight bind. "One of my associates referred to it as the 'Westlands death march,'" said Tom Stokely, a longtime water activist and member of the environmental group California Water Impact Network. "While Westlands is pursuing water and growing crops, in the long run it can't be sustained.""
Others don't agree: Gizmodo - Seriously, Stop Demonizing Almonds
How much water is needed to produce food and how much do we waste? http://www.theguardian.com/news/datablog/2013/jan/10/how-much-water-food-production-waste
How much water does it take to grow a hamburger? https://water.usgs.gov/edu/sc1.html
California’s Drought — Who’s Really Using all the Water? http://www.onegreenplanet.org/news/californias-drought-whos-really-using-all-the-water/
Meat Production Wastes Natural Resources http://www.peta.org/issues/animals-used-for-food/meat-wastes-natural-resources/
"In 2008, John Anthony Allan, a professor at King’s College London and the winner of the prestigious Stockholm Water Prize, urged people worldwide to go vegetarian because of the tremendous waste of water involved with eating animals."
"Agriculture uses about 80 percent of California’s developed water supply. Agricultural water users can develop more sustainable water use by expanding adoption of key modern irrigation technologies and practices, such as drip irrigation and precise irrigation scheduling. Some farmers are already employing these practices, which, extended, can reduce agricultural water use by 17 to 22 percent – or 5.6 to 6.6 million acre-feet of water annually. These savings are the equivalent to the surface water that Central Valley farms are lacking this year due to the drought."
The Water Footprint of Food http://www.gracelinks.org/1361/the-water-footprint-of-food
"For instance, wheat requires 132 gallons of water per pound, and a pound of cheese takes about 600 gallons. Therefore, a cheese sandwich represents approximately 100 gallons of water (and that’s just for a couple of cheese slices). Throw in a bag of potato chips and it takes about 150 gallons of water to make your lunch! Thirsty? If you feel like rinsing it down with a cold glass of milk, add an extra 100 gallons of water onto your tab. The sheer amount of water used to make the food we eat every day can be mind-boggling.
On average it takes about 108 gallons of water to produce one pound of corn. If that corn is then used as cattle feed, additional water is required for cleaning and processing. Factoring in feed and water, it can take around 1,800 gallons of water to produce a single pound of beef. Considering that the average American eats about 171 pounds of meat a year – three times the international average and twice the amount recommended for good nutritional health! – it’s clear that by eating less meat, you conserve water and eat a healthier diet."
Beef: The King of the Big Water Footprints http://www.gracelinks.org/blog/1143/beef-the-king-of-the-big-water-footprints
"So the question remains: Is there one figure that seems most accurate and useful? I lean towards the Water Footprint Network’s (WFN) 1,799 gallons of water per pound of beef figure for two reasons. First, they have created and standardized the rigorous methods behind water footprinting. Second, they use large, global data sets that incorporate many beef production systems from numerous countries."
This = 6813 L / lb = 15,000 L/kg = 15,000 water : 1 beef